Knowledge of force, gravity, friction, etc. is important for the 8th grade state test. However, simple machines are not on the 8th grade test. If you are running short on time and need to cut a competency out of the year, I would teach 2f (force) but not 2c (simple machines).
*Note - For 7.1, 7.2, and 7.3 guided practice, print out a 7.1 force gameboard and game cards for each group. You will need to take the time to cut up and write in some of the game cards, but the students get very invested in playing the game.
Lesson Plans
Magnetic Forces
Electric Forces
and Wheel and Axle
Assessments and Review